CN113107625A - Multi-heat-source wide-load low-pressure industrial steam supply system and working method - Google Patents
Multi-heat-source wide-load low-pressure industrial steam supply system and working method Download PDFInfo
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- CN113107625A CN113107625A CN202110567909.5A CN202110567909A CN113107625A CN 113107625 A CN113107625 A CN 113107625A CN 202110567909 A CN202110567909 A CN 202110567909A CN 113107625 A CN113107625 A CN 113107625A
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01K—STEAM ENGINE PLANTS; STEAM ACCUMULATORS; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES
- F01K13/00—General layout or general methods of operation of complete plants
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01K—STEAM ENGINE PLANTS; STEAM ACCUMULATORS; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES
- F01K13/00—General layout or general methods of operation of complete plants
- F01K13/02—Controlling, e.g. stopping or starting
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01K—STEAM ENGINE PLANTS; STEAM ACCUMULATORS; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES
- F01K17/00—Using steam or condensate extracted or exhausted from steam engine plant
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Abstract
The invention discloses a multi-heat-source wide-load low-pressure industrial steam supply system and a working method. When the high-load operation is carried out, the industrial steam supply source comes from middle exhaust steam; when the medium and high load operation is carried out, the industrial steam supply source still comes from the medium exhaust steam, but the heat supply valve needs to be moderately suppressed to meet the industrial steam supply pressure; when the low-load operation is carried out, the industrial steam supply source is used for supplying hot steam, and the hot steam is used for guiding the steam after the steam is discharged from the middle part through the hot press; and (4) low-load operation, and when the hot press breaks down, switching to a hot re-steam bypass steam supply pipeline. The invention has flexible operation mode, can ensure the requirements of industrial steam supply quality and steam supply quantity, and can remove the limitation of the adjustment capacity of the heat supply valve.
Description
Technical Field
The invention belongs to the field of cogeneration of heat and power for coal-fired power generating units, and particularly relates to a multi-heat-source wide-load low-pressure industrial steam supply system and a working method.
Background
With the rapid development of renewable energy sources and the increasing severity of air pollution problems, the power grid function of the coal-fired thermal power generating unit is gradually changed from a main body to an electric power regulation type, the peak regulation capability of the existing system of the unit is fully developed, and the operation flexibility of the unit is increased to the maximum extent. When the coal-fired generating set frequently participates in deep peak regulation, the unit for bearing industrial steam supply must ensure the reliability and stability of steam supply parameters, and the requirements of steam utilization enterprises need to be met according to quality and quantity, so that the problem of production reduction and even production stop caused by the reduction of steam quality and steam quantity of the steam utilization enterprises is avoided, and serious economic loss is caused.
A large number of coal-fired generating sets undertake external industrial steam supply through technical transformation, wherein a medium-exhaust steam extraction low-pressure steam supply technology based on medium-low pressure communicating pipe heat supply butterfly valve adjustment is generally applied. The industrial steam supply technology belongs to adjustable steam extraction, and when the unit operates under variable working conditions, the steam supply pressure and flow are adjusted through the opening of a valve so as to ensure the stability and reliability of industrial steam supply parameters. However, when the unit operates at a lower electric load, the throttle is further closed, and the pressure of the medium-exhaust steam is greatly increased, so that the medium-exhaust temperature is further increased. When the exhaust temperature exceeds the safety limit value, equipment safety hazards are caused, and the load of the cogeneration unit cannot be further reduced due to the fact that the cogeneration unit bears industrial steam supply. In addition, the valve is influenced by self-regulation characteristics and safety characteristics, the regulation capacity of the valve is very limited, and the requirement of deep peak regulation of a power grid cannot be met.
Therefore, the operation range of the currently applied adjustable steam extraction technology of the medium-low pressure communicating pipe is narrow, and the contradiction between the deep peak regulation requirement of the coal-electric machine set and the guarantee of the steam supply capacity is difficult to effectively solve.
Disclosure of Invention
The invention aims to solve the problems that the contradiction between the narrow operation range of a unit, the deep peak regulation requirement and the guarantee of the low-load industrial steam supply capacity is difficult to effectively solve due to the high low-load medium-low pressure exhaust temperature and the limited regulating capacity of a heat supply valve in the practical application of the conventional medium-low pressure communicating pipe adjustable steam extraction technology, and provides a multi-heat-source wide-load low-pressure industrial steam supply system and a working method.
In order to achieve the purpose, the wide-load low-pressure industrial steam supply system with multiple heat sources comprises a medium pressure cylinder, a low pressure cylinder and a hot press;
the intermediate pressure cylinder is connected with a boiler reheater through a hot re-pipeline and is connected with the low pressure cylinder through an intermediate and low pressure communicating pipe;
the hot re-pipeline is connected with the hot press through a driving pipeline, the middle-low pressure communicating pipe is connected with the hot press through an injection pipeline, and the hot press supplies steam to the outside through an industrial steam supply auxiliary pipeline.
The medium-low pressure communicating pipe is connected with an industrial steam supply main pipeline, the industrial steam supply main pipeline supplies steam to the outside, and a main reducing valve, a main desuperheater and a main stop valve are arranged on the industrial steam supply main pipeline.
The hot second pipeline is connected with a bypass pipeline, and a bypass pressure reducer and a bypass stop valve are arranged on the bypass pipeline.
And a heat supply valve is arranged on the middle and low pressure communicating pipe.
The industrial steam supply main pipeline is arranged at the upstream of the heat supply valve at the steam extraction position of the medium-low pressure communicating pipe.
The driving pipeline is provided with a driving stop valve and a driving desuperheater.
The injection pipeline is provided with an injection stop valve.
An auxiliary desuperheater and an auxiliary stop valve are arranged on the industrial steam supply auxiliary pipeline.
A working method of a multi-heat-source wide-load low-pressure industrial steam supply system is characterized in that when a unit operates at high load and the heat vapor pressure is not lower than the industrial steam supply pressure, all industrial steam supply is from a medium-low pressure communicating pipe, and medium-discharge steam is supplied outwards after being subjected to temperature and pressure reduction;
when the unit operates at medium and high load, and the medium exhaust pressure is lower than the industrial steam supply pressure, all industrial steam supply is from the medium and low pressure communicating pipe, the heat supply valve is partially opened, and the pressure of the medium exhaust steam is increased to meet the industrial steam supply pressure;
when the unit operates at low load and the pressure difference between the front and the back of the heat supply valve reaches the safety limit value given by a manufacturing plant, industrial steam supply comes from a medium-low pressure communicating pipe and a heat re-pipeline and is discharged outwards after being ejected by a hot press for temperature reduction;
the unit operates under low load, industrial steam is supplied from the hot re-pipeline, and is supplied out after temperature and pressure reduction.
When the unit operates at high load and the hot vapor pressure is not lower than the industrial steam supply pressure, the main stop valve is opened, and the driving stop valve, the injection stop valve, the auxiliary stop valve and the bypass stop valve are closed;
when the unit operates at medium and high load and the medium exhaust pressure is lower than the industrial steam supply pressure, the main stop valve is opened, and the driving stop valve, the injection stop valve, the auxiliary stop valve and the bypass stop valve are closed;
when the unit operates at low load and the front-back pressure difference of the heat supply valve reaches a safety limit value, the main stop valve and the bypass stop valve are closed, and the driving stop valve, the injection stop valve and the auxiliary stop valve are opened;
when the unit operates at low load and the hot press breaks down, the main stop valve, the injection stop valve and the auxiliary stop valve are closed, and the driving stop valve and the bypass stop valve are opened.
Compared with the prior art, the hot press is provided with the hot press, the driving steam is hot re-steam, and the injection steam is middle-discharge steam. When the high-load operation is carried out, the industrial steam supply source comes from middle exhaust steam; when the medium and high load operation is carried out, the industrial steam supply source still comes from the medium exhaust steam, but the heat supply valve needs to be moderately suppressed to meet the industrial steam supply pressure; when the low-load operation is carried out, the industrial steam supply source is used for supplying hot steam, and the hot steam is used for guiding the steam after the steam is discharged from the middle part through the hot press; and (4) low-load operation, and when the hot press breaks down, switching to a hot re-steam bypass steam supply pipeline. The invention has flexible operation mode, can ensure the requirements of industrial steam supply quality and steam supply quantity, and can remove the limitation of the adjustment capacity of the heat supply valve. And when large-flow industrial steam supply is carried out, one part of steam supply is self-heating re-steam, and the other part of steam supply is taken from middle exhaust steam, so that the phenomenon that middle exhaust blades are over-heated due to excessive extraction of middle exhaust steam is avoided, and the wide-load, safe and stable operation of the unit under the deep peak regulation state is really realized.
Drawings
FIG. 1 is a block diagram of the system of the present invention;
the system comprises a medium pressure cylinder 1, a medium pressure cylinder 2, a low pressure cylinder 3, a heat re-pipeline 4, a medium and low pressure communicating pipe 5, a heat supply valve 6, a hot press 7, a main reducing valve 8, a main desuperheater 9, a main stop valve 10, a driving stop valve 11, a driving desuperheater 12, an auxiliary desuperheater 13, an auxiliary stop valve 14, a driving pipeline 15, an injection pipeline 16, an auxiliary stop valve 17, an industrial steam supply main pipeline 18, an industrial steam supply auxiliary pipeline 19, a bypass pipeline 20, a bypass pressure reducer 21 and a bypass stop valve.
Detailed Description
The invention is further described below with reference to the accompanying drawings.
Referring to fig. 1, a multi-heat source wide-load low-pressure industrial steam supply system mainly comprises an intermediate pressure cylinder 1, a low pressure cylinder 2 and a hot press 6; the intermediate pressure cylinder 1 is connected with a boiler reheater through a hot re-pipeline 3, and the intermediate pressure cylinder 1 is connected with the low pressure cylinder 2 through an intermediate and low pressure communicating pipe 4; the hot press 6 is connected with the hot re-pipeline 3 through a driving pipeline 14, the hot press 6 is connected with the medium-low pressure communicating pipe 4 through an injection pipeline 15, and the hot press 6 supplies steam to the outside through an industrial steam supply auxiliary pipeline 18.
When the operation is carried out above the middle and high load, part of steam in the middle and low pressure communicating pipe 4 enters the industrial steam supply main pipeline 17, and the rest part of steam enters the low pressure cylinder 2; when the low-load operation is carried out, part of steam in the middle and low-pressure communicating pipe 4 enters the injection pipeline 15, and the rest part of steam enters the low-pressure cylinder 2. And (3) low-load operation, when the hot press 6 operates normally, part of steam in the hot re-pipeline 3 enters the driving pipeline 14, and the rest part of steam enters the intermediate pressure cylinder 1. When the low-load operation and the hot press 6 have faults, a part of steam in the hot re-pipeline 3 enters the bypass pipeline 19, and the rest part of steam enters the intermediate pressure cylinder 1.
And a heat supply valve 5 is arranged on the middle and low pressure communicating pipe 4. The industrial steam supply main pipe 17 is arranged in front of the heat supply valve 5 at the steam extraction position of the medium and low pressure communicating pipe 4.
The main industrial steam supply pipeline 17 is provided with a main pressure reducing valve 7, a main desuperheater 8 and a main stop valve 9. The drive line 14 is provided with a drive shut-off valve 10 and a drive desuperheater 11. An injection stop valve 16 is arranged on the injection pipeline 15. The auxiliary industrial steam supply pipeline 18 is provided with an auxiliary desuperheater 12 and an auxiliary stop valve 13. The bypass line 19 is provided with a bypass pressure reducing valve 20 and a bypass cut-off valve 21.
When the unit runs at a high load and the hot vapor pressure is not lower than the industrial vapor supply pressure, the main stop valve 9 is opened, the driving stop valve 10, the injection stop valve 16, the auxiliary stop valve 13 and the bypass stop valve 21 are closed, all the industrial vapor supply comes from the medium-low pressure communicating pipe 4, the heat supply valve 5 does not participate in regulation at the moment, and the medium-discharge vapor is supplied to the outside after being subjected to temperature and pressure reduction; when the unit runs at medium and high load, and the medium discharge pressure is slightly lower than the industrial steam supply pressure, the main stop valve 9 is opened, the driving stop valve 10, the injection stop valve 16, the auxiliary stop valve 13 and the bypass stop valve 21 are closed, all the industrial steam supply comes from the medium and low pressure communicating pipe 4, the heat supply valve 5 is closed to be small, and the medium and discharge steam is moderately pressurized to meet the industrial steam supply pressure; when the unit operates at low load, and the front and back pressure difference of the heat supply valve 5 reaches the safety limit value given by a manufacturing plant, the main stop valve 9 and the bypass stop valve 21 are closed, the drive stop valve 10, the injection stop valve 16 and the auxiliary stop valve 13 are opened, industrial steam is from the medium and low pressure communicating pipe 4 and the heat re-pipeline 3, and is externally supplied after being injected by the hot press for temperature reduction. When the unit is in low-load operation and the hot press 6 breaks down, the main stop valve 9, the injection stop valve 16 and the auxiliary stop valve 13 are closed, the drive stop valve 10 and the bypass stop valve 21 are opened, industrial steam is supplied from the hot recycling pipeline 3, and the industrial steam is supplied to the outside after being subjected to temperature reduction and pressure reduction.
The invention is suitable for the industrial steam requirement with the pressure range of 0.8-1.2MPa, the temperature lower than 300 ℃ and the flow rate more than 200 t/h.
Example (b):
a1000 MW unit turbine of a certain power plant is an N1000-25/600/600 type, ultra-supercritical, single-shaft, four-cylinder, four-steam-exhaust, once-intermediate-reheating and condensing turbine manufactured by Orient steam turbine Limited, and is required to bear external low-pressure steam supply parameters of 1.1MPa, 274 ℃ and 270t/h, and a low-pressure steam extraction position is a medium-low pressure communicating pipe.
When the heat supply valve is adjusted, the minimum operation load of the checking unit of the manufacturing plant is 866MW when the low-pressure steam supply of 270t/h is born under the influence of the adjusting characteristic of the heat supply valve and the axial thrust. If the unit deep peak shaving needs to further reduce the electric load, the hot exhaust pressure can not meet the steam requirement.
After the steam injection device is improved, the hot press is arranged, the driving steam is hot re-steam, and the injection steam is middle-discharge steam. When the electric load of the unit is lower than 866MW, the steam source comes from the middle exhaust pipeline and the heat re-pipeline. After accounting, when the unit is deeply peak-regulated to 40% THA (400MW) load operation, the steam supply pressure of 1.1MPa can still be met, the unit operation flexibility is greatly improved, and the full-load wide-area operation of the unit is really realized.
Claims (10)
1. A multi-heat source wide-load low-pressure industrial steam supply system is characterized by comprising an intermediate pressure cylinder (1), a low pressure cylinder (2) and a hot press (6);
the intermediate pressure cylinder (1) is connected with a boiler reheater through a hot re-pipeline (3), and the intermediate pressure cylinder (1) is connected with the low pressure cylinder (2) through an intermediate and low pressure communicating pipe (4);
the heat re-pipeline (3) is connected with the hot press (6) through a driving pipeline (14), the medium-low pressure communicating pipe (4) is connected with the hot press (6) through an injection pipeline (15), and the hot press (6) supplies steam to the outside through an industrial steam supply auxiliary pipeline (18).
2. A multi-heat-source wide-load low-pressure industrial steam supply system as claimed in claim 1, wherein the medium and low-pressure communicating pipe (4) is connected with an industrial steam supply main pipe (17), the industrial steam supply main pipe (17) supplies steam to the outside, and a main reducing valve (7), a main desuperheater (8) and a main stop valve (9) are arranged on the industrial steam supply main pipe (17).
3. A multi-heat-source wide-load low-pressure industrial steam supply system according to claim 1, characterized in that the heat re-pipe (3) is connected with a bypass pipe (19), and a bypass pressure reducer (20) and a bypass stop valve (21) are arranged on the bypass pipe (19).
4. A multi-heat-source wide-load low-pressure industrial steam supply system according to claim 1, wherein the medium and low-pressure communicating pipe (4) is provided with a heat supply valve (5).
5. A multi-heat-source wide-load low-pressure industrial steam supply system according to claim 4, wherein the main industrial steam supply pipeline (17) is arranged at the upstream of the heat supply valve (5) at the steam extraction position of the medium and low-pressure communicating pipe (4).
6. A multi-heat-source wide-load low-pressure industrial steam supply system according to claim 1, wherein the drive pipeline (14) is provided with a drive stop valve (10) and a drive desuperheater (11).
7. A multi-heat-source wide-load low-pressure industrial steam supply system according to claim 1, wherein the injection pipeline (15) is provided with an injection stop valve (16).
8. A multi-heat-source wide-load low-pressure industrial steam supply system according to claim 1, wherein the auxiliary industrial steam supply pipeline (18) is provided with an auxiliary desuperheater (12) and an auxiliary stop valve (13).
9. The working method of the multi-heat-source wide-load low-pressure industrial steam supply system according to claim 1, wherein when the unit is operated at a high load and the heat vapor pressure is not lower than the industrial steam supply pressure, all industrial steam supply is from the medium and low pressure communicating pipe (4), and medium-discharge steam is supplied to the outside after being subjected to temperature and pressure reduction;
when the unit operates at medium and high load, and the medium exhaust pressure is lower than the industrial steam supply pressure, all industrial steam supply comes from the medium and low pressure communicating pipe (4), the heat supply valve (5) is partially opened, and the pressure of the medium exhaust steam is increased to meet the industrial steam supply pressure;
when the unit operates at low load and the pressure difference between the front and the back of the heat supply valve (5) reaches the safety limit value given by a manufacturing plant, industrial steam is supplied from the medium-low pressure communicating pipe (4) and the heat re-pipeline (3), and is discharged outwards after being ejected by the hot press for temperature reduction;
the unit operates under low load, industrial steam is supplied from the hot re-pipeline (3), and is supplied out after temperature and pressure reduction.
10. The working method of the multi-heat-source wide-load low-pressure industrial steam supply system is characterized in that when the unit operates at high load and the heat vapor pressure is not lower than the industrial steam supply pressure, the main stop valve (9) is opened, and the driving stop valve (10), the injection stop valve (16), the auxiliary stop valve (13) and the bypass stop valve (21) are closed;
when the unit runs at medium and high load, and the medium discharge pressure is lower than the industrial steam supply pressure, the main stop valve (9) is opened, and the driving stop valve (10), the injection stop valve (16), the auxiliary stop valve (13) and the bypass stop valve (21) are closed;
when the unit runs at low load, and the front-back pressure difference of the heat supply valve (5) reaches a safety limit value, the main stop valve (9) and the bypass stop valve (21) are closed, and the driving stop valve (10), the injection stop valve (16) and the auxiliary stop valve (13) are opened;
when the unit is in low-load operation and the hot press (6) breaks down, the main stop valve (9), the injection stop valve (16) and the auxiliary stop valve (13) are closed, and the driving stop valve (10) and the bypass stop valve (21) are opened.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202110567909.5A CN113107625A (en) | 2021-05-24 | 2021-05-24 | Multi-heat-source wide-load low-pressure industrial steam supply system and working method |
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| CN202110567909.5A CN113107625A (en) | 2021-05-24 | 2021-05-24 | Multi-heat-source wide-load low-pressure industrial steam supply system and working method |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114353040A (en) * | 2021-11-30 | 2022-04-15 | 华能海南发电股份有限公司东方电厂 | Control system and method for heat rejection load of steam extraction heat supply unit |
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2021
- 2021-05-24 CN CN202110567909.5A patent/CN113107625A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114353040A (en) * | 2021-11-30 | 2022-04-15 | 华能海南发电股份有限公司东方电厂 | Control system and method for heat rejection load of steam extraction heat supply unit |
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